JPS585207B2 - Polyamideimide resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polyamideimide resin composition.

Currently, polyester varnishes are widely used as electrical insulating varnishes, especially varnishes for enameled wires, because they have relatively well-balanced mechanical properties, electrical properties, heat resistance, etc.

However, in recent years, as electric equipment has become smaller and lighter, there has been a demand for enamelled wire varnishes that have even better heat resistance and freon resistance.

Varnishes for enameled wire with good heat resistance and Freon resistance include polyimide varnishes, polyamideimide varnishes, and other highly heat-resistant varnishes. The resin itself is expensive, and there is a big problem in terms of cost.

Therefore, in order to improve the heat resistance of polyester-based varnishes for enameled wires, so-called polyester imide varnishes containing imide groups as part of the resin component have been proposed.

However, although polyesterimide has improved heat resistance compared to polyester, it has drawbacks in heat softening and freon resistance, and is not as good as polyamideimide.

Therefore, many studies have been conducted to solubilize polyamide-imide varnish with excellent heat resistance in general-purpose solvents such as cresol (for example, Japanese Patent Publication No. 46-29730,
Special Publication No. 49-30718, Special Publication No. 50-2099
3, Japanese Patent Publication No. 53-47157).

However, a resin with well-balanced heat resistance, freon resistance, mechanical properties, electrical properties, etc. has not yet appeared.

The present inventors have conducted intensive studies on heat-resistant resins that can be used in cresol-based solvents, and as a result, a part of the polyamide-imide resin component, which can only be synthesized in N-methylpyrrolidone, is soluble in cresol-based solvents. The present invention has been completed based on the use of a so-called solubilizing component as well as a branching component in order to maintain and improve heat resistance.

The present invention relates to a resin composition containing a resin and a solvent, the resin being an aromatic diisocyanate, a lactam, a polycarboxylic acid having an acid anhydride group, and the general formula (x +
T-R-(E-Y).

A compound represented by [X is a carboxyl group, Y is a carboxyl group, hydroxyl group or amino group, R is an aromatic, aliphatic, alicyclic or heterocyclic residue, n is an integer of 1 or more], 20 to 90 equivalents of lactam based on the total isocyanate equivalents
A compound represented by the above general formula is reacted in the presence of a cresol solvent, with the carboxyl group being in the range of 1 to 20 equivalent % based on the carboxyl groups and all the acid anhydride groups in the entire reaction system. The present invention relates to a polyamide-imide resin composition containing a cresol-based solvent (I) as a solvent.

The branching component represented by the general formula (X h-R-(-Y) n used in the present invention) is a component having a total of at least two carboxyl groups that can be converted into a resin by an amide bond and/or an imide bond with an aromatic diisocyanate. It may be any material as long as it also has other functional groups that can substantially serve as a branching component.

Considering flexibility, heat resistance, freon resistance, etc., a reaction product of a diisocyanate trimer, such as tolylene diisocyanate or isophorone diisocyanate trimer, and trimellitic anhydride, such as polyimide polycarboxylic acid, is used. , trimesic acid, tris(2-carboxyethyl)isocyanurate, etc. are also used.

The diisocyanate trimer can be prepared by known methods, for example, Japanese Patent Application No. 1983.
It can be prepared by the method described in No.-148820.

The branching component represented by the above general formula is used in an amount of 1 to 20 equivalent percent of the carboxyl group based on the carboxyl group and acid anhydride group of the entire reaction system.

If it is too large or too small, a well-balanced property of heat resistance and flexibility will not be exhibited.

If the amount is too large, the degree of branching may increase and gelation may occur during synthesis.

Similarly, the lactam, which is an important raw material for solubilizing cresol solvents, can generally be anything as long as it reacts with isocyanate groups or acid anhydride groups in cresol solvents and becomes soluble. , ε-caprolactam is preferred in consideration of reactivity and cost.

Although it depends on the intended use, for example, in the case of a heat-resistant enameled wire varnish, it is not necessary to add lactam in an amount equivalent to the isocyanate group (ε-caprolactam is considered to be difunctional).

If heat resistance, flexibility, and solubility are comprehensively considered, the amount should be in the range of 20 to 90 equivalent percent of the total isocyanate equivalent, so that it is substantially incorporated into the resin.

If it is too large or too small, it will not be possible to obtain a product with a good balance between heat resistance and flexibility and excellent freon resistance.

Preferred aromatic diisocyanates include 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, tolylene diisocyanate, xylylene diisocyanate, and the like.

A mixture of these aromatic diisocyanates may be used.

The polycarboxylic acid having an acid anhydride group is not particularly limited as long as it is a carboxylic acid or a derivative thereof having an acid anhydride group that reacts with an isocyanate group such as trimellitic anhydride.

If necessary, a part of the carboxylic acid containing an acid anhydride group can be converted into pyromellitic dianhydride, butanetetracarboxylic dianhydride, bicyclo-[2.2.2]-oct(7)-ene-2 :3.5:6-Carboxylic dianhydride such as 6-tetracarboxylic dianhydride and aliphatic or aromatic dibasic acid may be substituted.

In general, it is preferable to use trimellitic anhydride as the main component in consideration of heat resistance, cost, etc.

From the viewpoint of heat resistance, the amounts of the isocyanate component and the acid component to be used are selected so that the equivalent ratio of the isocyanate group to the carboxyl group and acid anhydride group is 0.90 to 1.2.

For the reaction, all the raw materials may be charged at the same time.To prevent fogging, the general formula for all isocyanate components (X+
r-R-OY) □, a lactam, and a cresol solvent were charged and reacted at 160 to 190°C for 1 to 3 hours, then a polycarboxylic acid containing an acid anhydride group was added, and the It is preferable to continue the reaction at a temperature of 10 to 20 hours.

The progress of the reaction can be determined by observing the generated carbon dioxide gas bubbles and the viscosity of the solution.

In addition to cresol, phenol,
Xylenol etc. can be used, and a mixed solvent may also be used.

Some of the synthesis solvents include aromatic organic solvents with high boiling points, such as xylene, N15SEKI HISOL-100, 150
(trademark for aromatic hydrocarbons manufactured by Nippon Petrochemical), cellosolve acetate, etc. can also be used.

The polyamide-imide resin composition thus obtained is further diluted with a polar solvent such as the above-mentioned cresol solvent N-methylpyrrolidone, dimethylformamide, dimethylacetamide, etc. to a resin content of 20 to 40% by weight and used as a varnish. used.

In this case, xylene, N15SEKI as a co-solvent
HISOL-100, cellosolve acetate, etc. may be used in combination.

The coating film created using the varnish prepared in this way exhibits good heat resistance, freon resistance, and flexibility, and can be used practically as a heat-resistant paint, a heat-resistant adhesive, a heat-resistant laminated material, and a varnish for electric wires. It was something.

Of course, various thermosetting resins as curing agents and various metal salts as leveling agents may be added.

By adding an epoxy resin to the polyamide-imide resin in the present invention, the appearance of the coating film is significantly improved and high-speed workability is also improved.

Examples of epoxy resins include bisphenol-based epoxy resins such as Shell Co.'s product names and Epikote 828.1001.1004.1007, Dow Chemical Co.'s product names, novolac-type epoxy resins such as DEN438, and Shikoku Kasei Co., Ltd. products. Heterocycle-containing epoxy resins such as TEP I C (trisglycidyl isocyanurate),
An alicyclic epoxy resin such as CH221 (trade name, manufactured by UCC Corporation) can be used, and there is no restriction on the epoxy resin used.

The mixing ratio of epoxy resins varies depending on the type, but in general, it may be determined depending on the application within a range that does not cause phase separation.

For example, for wire enamel, it is preferably about 1 to 30% by weight based on the resin content in the varnish.

As a mixing method, the epoxy resin to be mixed may be dissolved in cresol in advance and added to the polyamide-imide resin, or the epoxy resin may be directly added dropwise to the heated polyamide-imide resin solution.

In order to avoid thickening over time after addition of the epoxy resin, it is preferable to add the epoxy resin immediately before use.

By adding an alkoxy-modified amino resin to the polyamide-imide resin in the present invention, the appearance of the coating film is significantly improved and high-speed workability is also improved.

Alkoxy-modified amino resins are those obtained by subjecting an amine compound such as melamine, benzoguanamine, or urea to an addition condensation reaction with formaldehyde or paraformaldehyde, and then appropriately alkoxylating the methylol group with an alcohol such as methanol, ethanol, or propatoolbutanol. It may be a co-condensate or a mixture.

The reason is unknown, but butylated benzoguanamine
Alkoxy-modified benzoguanamine formaldehyde resins such as formaldehyde resins are effective.

These effects of addition are remarkable in resol-soluble polyamide-imide resins such as those of the present invention, and such effects are not observed in existing polyamide-imide resins that are soluble in N-methylpyrrolidone-based solvents.

The mixing ratio varies depending on the composition of the alkoxy-modified amino resin to be mixed, the molecular weight and functional group of the resin, but generally it may be determined depending on the application within a range that does not cause phase separation.

For wire enamel, it is preferably about 0.1 to 20% by weight based on the resin content in the varnish.

As for the mixing method, the alkoxy-modified amino resin solution to be mixed is dissolved in cresol in advance,
It may be added to the polyamide-imide resin, or the alkoxy-modified amino resin solution may be added directly to the heated polyamide-imide resin solution.

The temperature during mixing may be in the range of room temperature to 200°C, as long as it does not cause phase separation and allows uniform mixing.

By adding phenol formaldehyde resin to the polyamide-imide resin in the present invention, the appearance of the coating film is significantly improved and high-speed workability is also improved.

As the phenol formaldehyde resin, phenol formaldehyde resins, alkylphenol formaldehyde resins, modified phenol formaldehyde resins mainly based on these resins, etc. can be used, and there are no restrictions on the type.

Examples of the modified phenol formaldehyde resin include amine compound-modified phenol formaldehyde resins such as melamine-modified phenol formaldehyde resin, benzoguanamine-modified phenol formaldehyde resin, and urea-modified phenol formaldehyde resin, and the amino compound may be the alkoxy-modified amine resin described above.

The mixing ratio of the phenol formaldehyde resin varies depending on the molecular weight and the type of functional group contained, but in general, it may be determined depending on the application within a range that does not cause phase separation.

For wire enamel, it is preferably about 0.1 to 30% by weight based on the resin content in the varnish.

As a mixing method, the phenol formaldehyde resin to be mixed may be dissolved in cresol in advance and added to the polyamide-imide resin, or the phenol formaldehyde resin may be directly added dropwise to the heated polyamide-imide resin solution. good.

By adding a polyisocyanate having an isocyanurate ring to the polyamide-imide resin in the present invention, further improved high-speed workability can be obtained.

The polyisocyanate having an isocyanurate ring may be one obtained by trimerizing a polyisocyanate compound, such as aromatic diisocyanate,
Particularly preferred is a trimer obtained by reacting tolylene diisocyanate in the presence of a tertiary amine, or a polyisocyanate mixture having an isocyanurate ring containing a trimer.

The amount of polyisocyanate having an isocyanurate ring to be added depends on the polyfunctionality of the polyisocyanate to be added, but for wire enamel, it is preferably about 1 to 20% by weight based on the resin content in the varnish.

A mask material prepared in advance with phenol, Fresol, ε-caprolactam, etc. may also be used.

As for the addition method, it may be added to the polyamide-imide resin at room temperature, or it may be added directly to the heated polyamide-imide resin solution.

By adding a polyester resin to the polyamide-imide resin in the present invention, the curability is significantly improved.

The polyester resin may be any resin as long as it has an OH residue, and is not particularly limited, but the acid component may include terephthalic acid and/or
Alternatively, those using inophthalic acid are preferred.

In the production of polyester resins, it is preferable to use terephthalic acid and/or inphthalic acid as the acid component, but instead of terephthalic acid and isophthalic acid, lower alkyl esters thereof such as dimethyl terephthalate, monomethyl terephthalate, diethyl terephthalate, inophthalic acid Dimethyl, diethyl isophthalate, etc. may be used, or condensates of terephthalic acid and/or isophthalic acid with glycol, such as polyethylene terephthalate, polyethylene isophthalate, etc. may be used.

Of course, it is also possible to use acids such as adipic acid, succinic acid, phthalic acid, trimellitic anhydride, maleic acid, and imidodicarboxylic acid represented by general formula (1), which are commonly used in electrical insulating varnishes. .

(R is a divalent organic group) The imidodicarboxylic acid represented by the general formula (1) is prepared by reacting about 2 moles of trimellitic anhydride with 1 mole of diamine as described in, for example, Japanese Patent Publication No. 51-40113. You can get it.

The diamines used include 4,4'-diaminodiphenylmethane m-phenylenediamine, p-phenylenediamine, ■4-diaminonaphthalene, 4,4'-diaminodiphenyl ether, 4,4'-dimethylhebutamethylenediamine, Hexamethylenediamine, 4.4'
-Dicyclohexylmethanediamine, diaminodiphenylsulfone, etc. are used.

It goes without saying that imidodicarboxylic acids obtained by using diisocyanates instead of diamines can also be used.

Polyhydric alcohol is used as the alcohol component used in the production of the above-mentioned polyester resin having hydroxyl groups.

Examples of dihydric alcohols include ethylene glycol, diethylene glycol, neopentyl glycol, Methylolpropane, tris(2-hydroxyethyl)isocyanurate, pentaerythritol, etc. are used.

From the viewpoint of heat resistance, tris(2-hydroxyethyl)isocyanurate is preferably used.

The amount of polyester resin added is preferably about 1 to 300% by weight based on the resin content of polyamideimide in the varnish.

By adding an organic acid metal salt to the polyamide-imide resin in the present invention, the appearance of the coating film is significantly improved.

Examples of organic acid metal salts include dibutyltin laurate, dibutyltin acetate, manganese naphthenate,
Those commonly used as dryers include manganese octenoate, cobalt naphthenate, cobalt octenoate, zinc naphthenate, and zinc octenoate, and one or more of these may be used.

The organic acid metal salt is preferably 0.01% based on the resin content.
-10% by weight, more preferably 0.1-5% by weight.

The organic acid metal salt and the polyamide-imide resin may be mixed at a temperature ranging from room temperature to 200° C. to ensure uniform mixing, but there are no particular limitations.

These additives may be used alone or in combination.

When used in combination, the individual effects of each are synergized.

As a preferred combination when used in combination, Z
organic acid salt of n and phenol formaldehyde resin, phenol formaldehyde resin and alkoxy-modified amino resin, organic acid salt of Zn and alkoxy-modified amino resin, epoxy resin and phenol formaldehyde resin, polyisocyanate having an incyanurate ring and phenol formaldehyde resin, Examples include combinations of organic acid salts of Zn, phenol formaldehyde resins, and alkoxy-modified amine resins.

Additionally, other additives other than these epoxy resins, alcoquine-modified amino resins, phenol formaldehyde resins, polyisocyanates having isocyanurate rings, polyester resins, and organic acid metal salts include polyethers, polyamides, polyamideimides, polyimides, and polyester resins. It can also be modified using hydantoin, polysulfone, guanidine carbonate, benzotriazole, polyesterimide, polyesteramide, furan resin, etc.

For example, it is made from tris(2-hydroquinethyl) isocyanurate, ethylene glycol, tris(2-hydroxyethyl)isocyanurate, ethylene glycol, dimethyl temphthalate, 4,4'-diaminodiphenylmethane, trimellitic anhydride. polyesterimide, 6-nylon, 6,6-nylon, 1-
Examples include polyamides such as 2-nylon.

These additives are preferably added in an amount of 0.1 to 0.1 to the resin content.
It is used in a range of 30% by weight.

In addition, tertiary amines such as triethylamine, triethylenediamine, N-methylmorpholine, N-N-dimethylethanolamine, and dimethylaniline, alcohols such as tetrabutyl titanate and tetrapropyl titanate, etc. are added as curing catalysts. You can also ask questions.

When using a mixture of additives, the quantitative ratio is generally as follows:
It may be determined depending on the application within a range that does not cause phase separation.

For example, in the case of wire enamel, it is preferable that the total amount of additives is not more than 25% by weight based on the resin content.

A resin containing any one or more of an epoxy resin, an alkoxy-modified amino resin, a phenol formaldehyde resin, a polyisocyanate having an isocyanurate ring, a polyester resin, and an organic acid metal salt, if necessary, in addition to the polyamide-imide resin in the present invention. The composition is
It is baked onto a conductor to make an insulated wire.

In particular, when the resin composition of the present invention is used as a varnish for electric wires to produce insulated wires, the resin composition is applied 3 to 15 times by die drawing or felt drawing.

The baking temperature is not particularly limited, but baking is usually done at a temperature of about 250 to 500°C.

The insulated wire thus obtained has particularly excellent heat resistance, freon resistance, and flexibility.

Of course, as is commonly practiced in the industry, the above composition may be used as a component of a double-coated wire with resins such as polyester, polyesterimide, formal, etc., to provide similar heat resistance, freon resistance, and flexibility. An insulated wire with excellent flexibility can be obtained.

The present invention will be illustrated by comparative examples and an implementation section.

Comparative Example 1 (1) Synthesis of polyimide polycarboxylic acid The above components other than trimellitic anhydride and cresol were placed in a four-loaf flask equipped with a thermometer and a stirrer, heated to 140°C in a nitrogen stream, and then heated to the same temperature. The reaction was continued until the content of isocyanate groups (initial concentration: 48 weight percent) reached 25 weight percent.

The infrared spectrum of this thing has 1710 cm-1,14
Absorption of isocyanurate rings was observed at 10 cm, and absorption of isocyanate groups was observed at 2260 cm.

1500 g of cresol was added to the triplet thus obtained.
was added to make a homogeneous solution, then the temperature was raised to 140°C again, 342.91% of trimellitic anhydride was added, and while xylene was distilled off, the decarboxylation imidization reaction was carried out, and the temperature was raised to 200°C.
The reaction continued until the carbon dioxide gas was no longer produced.

(2) Synthesis of cresol-soluble polyamide-imide resin The above ingredients except trimellitic anhydride were placed in a four-loaf flask equipped with a thermometer, a stirrer, and a fractionating tube, and the temperature was raised to 180°C in a nitrogen stream. , the reaction is carried out for 90 minutes.

Next, trimellitic anhydride is added and the temperature is raised to 210°C.

The reaction was continued at 210° C. for 15 hours.

A varnish was obtained by adjusting the resin concentration to 25% by weight with cresol.

The viscosity of this product was 65 poise (30°C).

In the infrared absorption spectrum, an imide group absorption at 1780 cm' and an amide group absorption at 1650 cm' were observed.

Comparative Example 2 (1) Synthesis of polyimide polycarboxylic acid The above components other than trimellitic anhydride and N-methyl-2-pyrrolidone were treated in the same manner as in Comparative Example 1 (1), with an isocyanate group content of 25% by weight. The reaction proceeded until it was completed.

The trimer thus obtained was added to N-methyl-2-pyrrolidone 565. OS' was added, and then trimellitic anhydride 342.9S' was added, the temperature was raised to 150°C, and the reaction was continued until no carbon dioxide gas was generated.

(2) Synthesis of cresol-soluble polyamide-imide resin Similarly to Comparative Example 1, a cresol-soluble polyamide-imide resin was synthesized using the above components.

The resulting resin was adjusted to a resin concentration of 25% by weight with cresol to obtain a varnish.

The viscosity of this product was 60 poise (30°C).

Example 1 A varnish was synthesized in the same manner as in Comparative Example 1 (2), and the resin concentration was adjusted to 25% by weight using cresol.

The viscosity of this product was 45 poise (30°C).

In the infrared absorption spectrum, imide group absorption was observed at 1780 cm', and amide bond absorption was observed at 1650 cm'.

Example 2 A varnish was synthesized in the same manner as in Comparative Example 1 (2), and the resin concentration was adjusted to 25% by weight using cresol.

The viscosity of this product was 60 poise (30°C).

In the infrared absorption spectrum, both imide group absorption at 1780 cm' and amide group absorption at 1650 cm' were observed.

The resulting varnish was further coated with alkoxy-modified amine resin ML-20 (manufactured by Hitachi Chemical) as a curing agent.6. i
, Epicote 10076, Of and phenol formaldehyde resin PR-2084W (To Hitachi Chemical, To,) 1
0.01 was added.

Example 3 The above ingredients except trimesic acid and trimellitic anhydride were stirred using a thermometer, then placed in a four-loaf flask with a fractionator tube attached, and the temperature was raised to 180°C in a nitrogen stream and reacted for 90 minutes. Let's do it.

Next, the temperature is lowered to 160°C, trimesic acid and trimellitic anhydride are added, and the temperature is raised to a temperature at which cresol refluxes.

The reaction proceeded at this temperature for 10 hours. A varnish was obtained by adjusting the resin concentration to 23% by weight with cresol.

The solution viscosity of this product is 83 poise (30°C), and the reduced specific viscosity is 0.28 (0.5 g/dimethylformamide 10
0ml solution).

The resulting varnish was further added with an imide-modified polyester resin Isomid 6 (manufactured by Schenectaday Co., Ltd.) as a curing agent.
0.0 g and 0.5 g of zinc naphthenate were added.

Example 4 A varnish was synthesized in the same manner as in Example 3 using the above components to have a resin concentration of 24% by weight.

The solution viscosity of this product was 83.0 poise (at 30° C.), and the reduced specific viscosity was 0.27 (0.5 g/100 ml of dimethylformamide solution).

40 g of a bisphenol type epoxy resin, Epicoat 1001 (manufactured by Shell) was added to the obtained varnish as a curing agent.

Example 5 A varnish was synthesized in the same manner as in Example 3 except that trimesic acid was replaced with tris(2-carboxyethyl)isocyanurate, and the resin content was adjusted to 25% by weight.

The solution viscosity of this product was 45 poise (30°C).

Example 6 Synthesis was carried out in the same manner as in Comparative Example 1 (2), and then polyester resin 15onel 200 (manufactured by Schenectaday Co., Ltd.)
100, Of was added.

The viscosity of this product was 85 poise (30°C) when the resin concentration was adjusted to 30% by weight with cresol.

Table 1 shows the characteristics of the insulated wire made using the obtained varnish.
It was shown to.

Characteristic tests were conducted according to JIS C3003.

(However, the cut-through load was 2 kg.

) Compared to the cresol-soluble polyamideimide of Comparative Example 1.2, which was synthesized using ε-caprolactam in an amount equivalent to 1.5 times the total amount of isocyanate, the synthesis was performed with careful attention to the contents of the branched component and ε-caprolactam. Each of the electric wires in Examples 1 to 6 is excellent in heat resistance (cut-through), flexibility, and freon resistance. It can be seen that it can be used as a material, especially as a varnish for electric wires.

Claims (1)

[Scope of Claims] 1. A resin composition containing a resin and a solvent, wherein the resin is an aromatic diisocyanate, a lactam, a polycarboxylic acid having an acid anhydride group, and a polycarboxylic acid having the general formula (X molecule -R-eY
) n (X is a carboxyl group, Y is a carboxyl group,
a hydroxyl group or an amino group, R is an aromatic, aliphatic, alicyclic or heterocyclic residue, and n is an integer of 1 or more.
The range is 0 equivalent%, and the compound represented by the above general formula,
A polyamide-imide resin soluble in a cresol solvent obtained by reacting the carboxyl group in the presence of a cresol solvent in a range of 1 to 20 equivalent % based on the carboxyl group and acid anhydride group in the entire reaction system ( A polyamide-imide resin composition comprising I) and a cresol solvent (II) as a solvent. 2 General formula (X-+U-R→Y). The polyamide-imide resin composition according to claim 1, wherein the compound represented by is a reaction product of a polyisocyanate having an isocyanurate ring and a polycarboxylic acid having an acid anhydride group. 3 General formula (X+r-R-+Y). The polyamide-imide resin composition according to claim 1, wherein the compound represented by is trimesic acid. 4. The polyamide-imide resin composition according to claim 1, wherein the compound represented by the general formula (Xh-R-(-Y)) is tris(2-carboxyethyl)isocyanurate. 5. Further, an epoxy resin , an alkoxy-modified amine resin, a phenol formaldehyde resin, a polyisocyanate having an isocyanurate ring, a polyester resin, and an organic acid metal salt. .